Saturating asphalt



"Patentec'lJune 15, 1943 SATURATING ASPHALT Joseph C. Roediger, Brooklyn, N. Y., assignor to Standard Oil Development Company, a corporation of Delaware No Drawing. Application November 16, 1939,

Serial No. 304,705

3 Claims.

' This invention relates to improvements in saturating materials such as rag felt, asbestos paper, etc. with asphalts and particularly when using asphalts that are solid at ordinary temperatures and are applied in a molten state at elevated temperatures.

In the preparation of asphalt shingles, building boards and other materials wherein rag felt, asbestos paper, etc. are coated with asphalt, an elevated temperature of about 400 F. is required. The rag felt or other fibrous material that is used generally contains small amounts of moisture, which moisture cannot be readilly removed Without subjecting the rag felt to elevated temperatures over extended periods of time. When the rag felt containing small percentages of moisture is contacted with the hot asphalt that is used to saturate the rag felt, there is a marked foaming tendency of the asphalt which is believed to be due to the small percentage of moisture present in the rag felt. In roofing manufacture the use of saturants with high (bad) foaming qualities may affect the efliciency of the saturation and also result in an overflow of the saturant from the saturating kettles. This tendency to foam has been reduced in the past by the addition of stearic acid and other nonasphaltic materials which materially increased the cost of the product and sometimes also affected the weathering properties of the asphalt.

It is an object of this invention to prepare an asphaltic material which will not foam excessively when subjected to an elevated temperature and used to saturate a fibrous material containing a small percentage of moisture.

Another object of this invention is to provide an asphaltic material consisting solely of hydrocarbon compounds that does not foam excessively.

According to this invention, it is found possible to blend various asphalts of the same or difierent crudes and thereby regulate the foaming tendency of the asphalt. As an example of this improvement to be obtained, a 260 seconds Furol viscosity at 210 F. flux asphalt produced by straight reduction in a pipe still of a C01- ombian crude was blended with an asphalt oxidized from the same flux asphalt to 241 and 280 F. softening points, respectively. The final blends were of 160/200 penetration and are compared in respect to foaming properties with a 160/200 penetration asphalt produced by direct oxidation of the 260 seconds Furol flux itself. The desired improvement in foaming tendency is accomplished by blending a straight reduced asphalt of relatively low consistency with an oxidized asphalt of relatively high consistency.

The foaming of the asphalts was compared by test method No. 1 in which:

. 200 grams of the asphalt under test are heated to 420 F. and 185 grams of this are poured into a thin walled cylindrical copper container open at the top, having an inside diameter of 4%; inches and 11 inches high, with small lugs placed 1 2 3 5, 6, 7, 8, 9 and 10 inches from the bottom. The container is well lagged on the sides but not on the bottom. The asphalt and container is maintained at a temperature of 400 F. plus or minus 3 F. A sheet of blotting paper, 3 X 3 inches in area, is air dried and moistened with 3.3 ml. of water in such a manner that even saturation of the paper is obtained in approximately 45 seconds. The wet paper is immersed in the hot asphalt and pushed to the bottom of the container with a long stirring rod.

. Observations are made of the maximum height to which the foam rises, and the period of time from the introduction of the water-moistened paper until the foam has subsided to the lug placed 2 inches from the bottom of the container, this being the subsidence time. As the foam subsides the stirring rod is gently run around the edge of the foam in order to promote even subsidence. and to more closely detect the time at wh ch the foam reaches the 2 inch lug.

Foam test #1 Foaming properties 160/200 Pen. Colombian asphalt saturant Max. Time to height of complete foam, subsidence, inches seconds Oxidized from 260 Fowl/210 F. flux 3.85 836 By blending 73.8%-260 Furol-flux,

26295-241 S. P. oxid. asph. 3. 25 395 By blending 74.6%-260 Furol-flux,

25.4%280 S. P. oxid. asph A. no, 3. 334

according to the following test method No. 2 in which:

A sample of 250 grams of the asphalt is brought to a temperature of 400 F. in a 1000 cc. tall form Pyrex beaker of internal diameter approximately 3 inches and height approximately 7 inches. A 3-inch wide strip of standard 52# rag felt 12 inches in length is placed in an oven main tained at 220 F., dried for 30 minutes, removed, allowed to cool in a desiccator and cc. of water evenly distributed over a 3 square inch area at the end of the felt. The strip of felt is then held vertically with the damp end on the bottom, dipped into the hot molten asphalt to the full depth of the liquid, held there for 15 seconds and removed. An interval of one minute is allowed between wetting and placing the felt in the asphalt. During the immersion period the felt is slowly revolved (l to 1 complete turns) to evenly distribute the foam. Upon removal of the felt from the asphalt, it is held with one corner down and the foam allowed to drip from the felt for a period of about 5 seconds. The seconds required for the first clear spot and the disappearance of Furthermore, this blending procedure for improving the foaming properties of an asphalt would permit more flexible operation in the refinery since only two materials, namely, low viscosity flux and high softening point oxidized asphalt, would be required as subsequent blending in the proper proportions would only be necessary to meet the different saturating asphalt specifications required by different purchasers.

In addition, saturating asphalts thus produced by blending can be oxidized to coating asphalts without any impairment of the weathering characteristics or physical properties over that obtained on coating asphalts produced from the usual saturating asphalts.

It is not necessary, to obtain this improvement in foam, that the flux and oxidized asphalt be obtained from the same crude source, as mixtures of ingredients obtained from different cr-udes may be used. When blending fluxes and oxidized asphalts of different crude bases, allowance is made for the natural foaming tendencies of these ingredients as a Venezuelan flux has less foaming tendency than that produced from Colombian flux. Consequently, in cross blending asphalts from different crude sources, the predominant proportion of the final blend should consist of that fiux made from the source having the lower foaming tendency in order to attain the maximum improvement; e. g. Venezuelan flux and Colombian 220/235 softening point oxidized asphalt rather than Colombian flux and Venezuelan 220/235 softening point oxidized asphalt. However, improvement is still obtained if this is not carried out, and the relative improvement will be governed by the asphalt source predominant in the blend.

The foam properties of different blends are illustrated in the table following:

Saturant Physical Composition of flux inspections Prepared by- 8.1. Pen.

l i00%78/83 S. P. Venez. flux. Oxidation to, 105 105 2 70%78/83 S. P. Vcnez. flux, 2l%220/235 S. P. oxidized Venezuelan asphalt Blended to 104 I05 3 74%-78/83 S. P. Venez. flux,

26%-220/235 S. P. Colombian oxidized asphalt do I05 100 4 72%-S0 S. P. Colombia flux,

28%220/235 S. P. Venezuelan oxidized asphalt... J03 180 5 719 S. P. Colombian flux,

29%220/235 S. P. Colom- 0 10093-80 S. P, Colombian flux Oxidized to. 106 I72 Foam properties by test No. 2

Composition of flux Time Time gig to 1st to total rige cleatr clearspo ance, Inches seconds seconds 1 l00%78,l83 S. P. Venez. flux i 2 275 930 2 76%78/83 S. P. Vencz. flux,

24%220/235 S. P. oxidized Venezuelan asphalt 2% M7 535 3 74%78/80 S. P. Vcnez. flux, 26%

220/235 S. P. Colombian oxidized asphalt l. 2% 22') 910 4 72%80 S.I. Colombian flux, 28%- 220/235 S. P. Venezuelan oxidized asphalt 2 25 1,005 7l%80 S. P, Colombian flux, 29%220/235 S. P. Colombiain oxidized asphalt, 2); 355 900 6 %R0 S. P. Colombian flux... 2k. 375 1,175

I claim:

The method of preparing a building material which comprises impregnating at temperatures above the boiling point of water, a fibrous material containing moisture with a mixture of straight reduced asphalt of relatively low consistency having a softening point ranging from 78 to 83 F. and an oxidized asphalt from a straight reduced crude of relatively high consistency whereby excessive foaming of the mixture is prevented.

2. A method of preparing a building material which comprises impregnating at temperatures above the boiling point of water, a fibrous material containing moisture with a mixture of straight reduced asphalt of relatively low consistency having a softening point ranging from 78 to 83 F. and an oxidized asphalt from a straight reduced crude of relatively high consistency having a softening point of at least 240 F. whereby excessive foaming of the mixture is prevented.

3. The method of preparing a building material which comprises impregnating at temperatures above the boiling point of water. a fibrous material containing moisture with a mixture of a straight reduced asphalt of relativeli. low consistency having a Furol viscosity of at least 100 seconds at 210 F.. and an oxidized asphalt from a straight reduced crude of relatively high consistency having a softening point ranging from 220 to 235 F. whereby excessive foaming of the mixture is prevented.

JOSEPH C. ROEDIGER. 

